The sand valley was vast, surrounded by towering sand dunes, with the valley floor full of sandthorn shrubs. Where could the underground river be in such a large area? Luo Zheng looked at Cao Xi in surprise. Cao Xi glanced around a few times, rushed to the center, and continued to observe. Soon, he dashed towards a dense patch of sandthorn foliage and said to Luo Zheng, "The sandthorn trees here are greener than the surroundings, indicating the water content is highest. The underground river is beneath us."
"Alright, I'll dig." Luo Zheng thought it made sense and quickly agreed, ready to start.
"No need, I'll start first." Cao Xi hurriedly said.
Luo Zheng looked at Cao Xi in surprise. How could he let a lady handle such hard work first? He was about to get to work with his military shovel when he saw Cao Xi put down her backpack and take out three cylindrical objects, each about two feet long, with a black appearance of unknown material. Puzzled, he asked, "What are these things?"
